Physical Science module 1 PDF

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Physical ScienceQuarter 2 – Module 1Ancient AstronomyPhysical Science Alternative Delivery Mode Quarter 2 – Module 1: Ancient Astronomy First Edition 2020Republic Act 8293, Section 176 states that “no copyright shall subsist in any work of the Government of the Philippines. However, prior approval o...

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Physical Science Quarter 2 – Module 1 Ancient Astronomy

Physical Science Alternative Delivery Mode Quarter 2 – Module 1: Ancient Astronomy First Edition 2020 Republic Act 8293, Section 176 states that “no copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties.” Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Secretary: Leonor Magtolis Briones Undersecretary: Diosdado M. San Antonio Development Team of the Module Writers: X-handi B. Fallarna Editors: Priscilla D. Domino, Felipa A. Morada Reviewers: Rogelio D. Canuel, Elmer C. Bobis, Felipa A. Morada Illustrator: John Albert Rico Layout Artist: Elsie R. Reyes Pamela A. Lalusin, Mary Grace L. Asa Management Team: Wilfredo E. Cabral, Regional Director Job S. Zape Jr., CLMD Chief Elaine T. Balaogan, Regional ADM Coordinator Homer N. Mendoza, Schools Division Superintendent Catherine V. Maranan, Assistant Schools Division Superintendent Lorna R. Medrano, CID Chief Edita T. Olan, EPS In-charge of LRMS Editha M. Malihan, EPS

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Gate 2 Karangalan Village,Barangay San Isidro Cainta, Rizal 1800 02-8682-5773/8684-4914/8647-7487 [email protected]/[email protected]

Physical Sciences Quarter 2 – Module 1 Ancient Astronomy

Introductory Message For the facilitator: Welcome to the Physical Science Grade 11 Alternative Delivery Mode (ADM) Module on Ancient Astronomy! This module was collaboratively designed, developed and reviewed by educators both from public and private institutions to assist you, the teacher or facilitator in helping the learners meet the standards set by the K to 12 Curriculum while overcoming their personal, social, and economic constraints in schooling. This learning resource hopes to engage the learners into guided and independent learning activities at their own pace and time. Furthermore, this also aims to help learners acquire the needed 21st century skills while taking into consideration their needs and circumstances. In addition to the material in the main text, you will also see this box in the body of the module:

Notes to the Teacher This contains helpful tips or strategies that will help you in guiding the learners.

As a facilitator, you are expected to orient the learners on how to use this module. You also need to keep track of the learners' progress while allowing them to manage their own learning. Furthermore, you are expected to encourage and assist the learners as they do the tasks included in the module.

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For the learner: Welcome to the Physical Science 11 Alternative Delivery Mode (ADM) Module on Ancient Astronomy! The hand is one of the most symbolic parts of the human body. It is often used to depict skill, action and purpose. Through our hands we may learn, create and accomplish. Hence, the hand in this learning resource signifies that as a learner, you are capable and empowered to successfully achieve the relevant competencies and skills at your own pace and time. Your academic success lies in your own hands! This module was designed to provide you with fun and meaningful opportunities for guided and independent learning at your own pace and time. You will be enabled to process the contents of the learning resource while being an active learner. This module has the following parts and corresponding icons: What I Need to Know

This will give you an idea of the skills or competencies you are expected to learn in the module.

What I Know

This part includes an activity that aims to check what you already know about the lesson to take. If you get all the answers correctly (100%), you may decide to skip this module.

What’s In

This is a brief drill or review to help you link the current lesson with the previous one.

What’s New

In this portion, the new lesson will be introduced to you in various ways such as a story, a song, a poem, a problem opener, an activity or a situation.

What is It

This section provides a brief discussion of the lesson. This aims to help you discover and understand new concepts and skills.

What’s More

This comprises activities for independent practice to solidify your understanding and skills of the topic. You may check the answers to the exercises using the Answer Key at the end of the module.

What I Have Learned

This includes questions or blank sentence/paragraph to be filled in to process what you learned from the lesson.

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What I Can Do

This section provides an activity which will help you transfer your new knowledge or skill into real life situations or concerns.

Assessment

This is a task which aims to evaluate your level of mastery in achieving the learning competency.

Additional Activities

In this portion, another activity will be given to you to enrich your knowledge or skill of the lesson learned. This also tends retention of learned concepts.

Answer Key

This contains answers to all activities in the module.

At the end of this module you will also find:

References

This is a list of all sources used in developing this module.

The following are some reminders in using this module: 1. Use the module with care. Do not put unnecessary mark/s on any part of the module. Use a separate sheet of paper in answering the exercises. 2. Don’t forget to answer What I Know before moving on to the other activities included in the module. 3. Read the instruction carefully before doing each task. 4. Observe honesty and integrity in doing the tasks and checking your answers. 5. Finish the task at hand before proceeding to the next. 6. Return this module to your teacher/facilitator once you are through with it. If you encounter any difficulty in answering the tasks in this module, do not hesitate to consult your teacher or facilitator. Always bear in mind that you are not alone. We hope that through this material, you will experience meaningful learning and gain deep understanding of the relevant competencies. You can do it!

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What I Need to Know

This module was designed and written with you in mind. It is here to help you to explain how the Greeks knew that the Earth is Spherical. The scope of this module permits it to be used in many different learning situations. The language used recognizes the varied vocabulary level of students. The lessons are arranged to follow the standard sequence of the course. But the order in which you read them can be changed to correspond with the textbook you are now using. The module contains discussion about what early philosophers thought about the shape of the Earth. After going through this module, you are expected to: 1. discuss the thoughts of philosophers about the shape of the Earth; 2. describe the size of the Earth; and 3. realize the importance of the shape of the Earth.

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What I Know Directions: Unscramble the letters of each word related to ancient astronomy using the clues that describe it. Write it on the line provided. KRGEES

_______________________ 1. They are much noted for their contributions in different fields. They were not only great philosophers but great scientists and mathematicians as well.

CIMELOTP LEDOM

_______________________ 2. It claims that the planets moved in a complicated system of circles. This model also became known as the Ptolemic System.

TOBALE R O D I H S P E ______________________3. The shape of the Earth. It has bulging equator and squeezed poles. THONR SRAT

_______________________4. It was believed to be in fixed position in the sky. However, when the Greeks traveled to places nearer the equator, like Egypt, they noticed that it is closer to the horizon.

S A R T I T L O E______________________5. A student of Plato and considered as one of the great philosophers of his time; his earth-centered view dominated for almost 2,000 years. CEILSPE

______________________6. An astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured by passing into the shadow of another body or by having another body pass between it and the viewer.

HSAWOD

_______________________7. A dark (real image) area where light from a light source is blocked by an opaque object.

RAETOSHTENSE _______________________8. A Greek philosopher who computed the circumference of the Earth and who gave the most accurate size during their time.

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TR ERGRODAE MOITON

_______________________9. An apparent change in the movement of the planet through the sky. It is not real in that the planet does not physically start moving backwards in its orbit. It just appears to do so because of the relative positions of the planet and Earth and how they are moving around the Sun.

WTINRE L O S I C T E S _____________________10. A moment when the Sun's path in the sky is farthest south in the Northern Hemisphere or farthest north in the Southern Hemisphere. MMUSRE L O S I C T E S _____________________11. The longest day of the year. In the Northern Hemisphere it is in June, while in the Southern Hemisphere it's in December. SHLEOICETNRIM ______________________12. The astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System. TRSIMEGOENC _______________________13. Any theory of the structure of the solar system (or the universe) in which Earth is assumed to be at the center of it all. COLNIUAS SCOEPRNIUC _______________________14. He considered the sun as the stationery center of the universe. He classified Earth as a planet just like Mercury, Venus, Mars, Jupiter, and Saturn. LLIEAGO G I A L I L E ________________________15. He was the greatest Italian scientist of the Renaissance. Due to the telescope, he was able to discover and observe important astronomical facts such as lunar craters, the phases of the Venus, the moons of Jupiter, sun spots, and the sizes of the stars.

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Lesson

Ancient Astronomy

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The Greeks are very much noted for their major contributions in different fields. They were not only great philosophers. They were great scientists and mathematicians as well. It was in Greece that the Golden Age of early astronomy was centered. Being philosophers, the Greeks used philosophical arguments to explain the natural events happening around them including the movements of the stars and other heavenly bodies. But they were also observers. They made use of their observational data to explain certain events. They were the ones who measured the sizes and the distances of the sun and the moon using the basics of geometry and trigonometry which they also developed. The early Greeks had a geocentric view of the earth. For them, it was the center of the universe; hence, a motionless sphere. The sun, moon, Mercury, Venus, Mars, Jupiter, and Saturn orbited the Earth. The Greeks also believed that stars traveled daily around the earth. However, they all stayed in a transparent, hollow sphere located beyond the planets. They called this sphere as the celestial sphere.

What’s In

Matching Type. Directions: Match the Greek astronomers in column A with their important findings in column B. Write the letter on the space provided before each number. Column A ________1. Hipparchus ________2. Aristarchus ________3. Eratosthenes ________4. Anaxagoras ________5. Eudoxus

Column B A. He proposed a system of fixed spheres. He believed that the sun, the moon, the five known planets and the stars were attached to these spheres. B. He was able to explain what causes the phases of the moon. According to him, the moon shone only by reflected sunlight.

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C. The very first Greek to profess the heliocentric view. He learned that the sun was many times farther than the moon and it was much larger than the earth. C. He made the first successful attempt to determine the size of the earth. He did this by applying the geometric principle. D. He is considered as the greatest of the early Greek astronomers. He observed the brightness of 850 stars and arranged them into order of brightness or magnitude. E. He was a student of Plato. For him, the earth is spherical in shape since it always casts a curved shadow when it eclipses the moon.

Notes to the Teacher Have you ever wondered what the philosophers in ancient astronomy thought about the shape of the Earth? They may have different beliefs and ideas but surprisingly, we used these to settle our curiosity in recent times. There are three good reasons to study the history of astronomy. First, history itself is fascinating. Second, you will understand the facts of astronomy better if you know why astronomers came to believe such incredible things. And third, the history of once-controversial ideas can shed light on scientific controversies that are still alive today. This chapter begins the story of the greatest scientific controversy of all time: the battle over earth's place in the universe. Is the earth unique, occupying a special place at the center of the universe? Or is it just another planet, drifting through space like the rest of the heavenly bodies? Today, every school child is taught that the second view is correct. But only a few hundred years ago, this view was considered absurd and even blasphemous. Let's try to understand why.

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What’s New

How do you see the shape of the Earth? Let’s try to understand this by performing this song. The Shape of the Earth is Round In the tune of “The Wheels on the bus go round and round” By: X-handi B. Fallarna

The shape of the Earth is round, just round Round, just round Round, just round The shape of the Earth is round, just round All this time

The Greek philosophers had thought it’s flat, Some thought it’s round, some thought it’s round The Greek philosophers had thought it’s flat, But they got it wrong!

North Star, eclipse, and sailing ship, Moon’s shadow from Earth’s relationship These conclude that the Earth is round All this time!

Excellent, you are a great singer!

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What is It

Key Terms  

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 

Oblate spheroid: the shape of the Earth. It has bulging equator and squeezed poles. Solstice: either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days. Eclipse: an obscuring of the light from one celestial body by the passage of another between it and the observer or between it and its source of illumination. Heliocentrism: the astronomical model in which the Earth and planets revolve around the Sun. Geocentrism: any theory of the structure of the solar system (or the universe) in which Earth is assumed to be at the center of it all.

Have you ever wondered what the philosophers in ancient astronomy thought about the shape of the Earth? Learn About It! Around 500 B.C., most Greeks believed that the Earth was round, not flat. It was Pythagoras and his pupils who were first to propose a spherical Earth. In 500 to 430 B.C., Anaxagoras further supported Pythagoras' proposal through his observations of the shadows that the Earth cast on the Moon during a lunar eclipse. He observed that during a lunar eclipse, the Earth's shadow was reflected on the Moon's surface. The shadow reflected was circular. Around 340 B.C., Aristotle listed several arguments for a spherical Earth which included the positions of the North Star, the shape of the Moon and the Sun, and the disappearance of the ships when they sail over the horizon. North Star The North Star was believed to be at a fixed position in the sky. However, when the Greeks traveled to places nearer the equator, like Egypt, they noticed that the North Star is closer to the horizon. The Shape of the Sun and the Moon Aristotle argued that if the Moon and the Sun were both spherical, then perhaps, the Earth was also spherical. Disappearing Ships If the Earth was flat, then a ship traveling away from an observer should become smaller and smaller until it disappeared. However, the Greeks observed that the ship became smaller and then its hull disappeared first before the sail as if it was being enveloped by the water until it completely disappeared.

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The Size of the Spherical Earth Ancient scholars tried to provide proof of a spherical Earth and its circumference through calculations. It was Eratosthenes who gave the most accurate size during their time. While he was working at the Library of Alexandria in Northern Egypt, he received correspondence from Syene in Southern Egypt which stated that a vertical object did not cast any shadow at noontime during the summer solstice. But this was not the case in Alexandria where, at noon time during the summer solstice, a vertical object still casts a shadow. These observations could only mean that the Sun, during this time in Alexandria, was not directly overhead.

Figure 1: Shows how Eratosthenes measured the circumference of the Earth.

Eratosthenes then determined the angle the Sun made with the vertical direction by measuring the shadow that a vertical stick cast. He found out that in Alexandria, the Sun makes an angle of 7.2° from the vertical while 0° in Syene. To explain the difference, he hypothesized that the light rays coming from the sun are parallel, and the Earth is curved. From his measurements, he computed the circumference of the Earth to be approximately 250 000 stadia (a stadium is a unit of measurement used to describe the size of a typical stadium at the time), about 40 000 kilometers. Our understanding about the different heavenly bodies can be credited to the important findings of the following Greek astronomers: a. Anaxagoras Anaxagoras was able to explain what causes the phases of the moon. According to him, the moon shone only by reflected sunlight. Since it is a sphere, only half of it illuminated at a time. This illuminated part that is visible from the earth changes periodically. b. Eudoxus Eudoxus proposed a system of fixed spheres. He believed that the Sun, the moon, the five known planets and the stars were attached to these spheres which carried the heavenly bodies while they revolved around the stationary Earth.

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c. Aristotle Aristotle was a student of Plato. For him, the earth is spherical in shape since it always casts a curved shadow when it eclipses the moon. He also believed that the earth was the center of the universe. The planets and stars were concentric, crystalline spheres centered on the earth. d. Aristarchus Aristarchus is the very first Greek to profess the heliocentric view. The word helios means sun; centric means centered. This heliocentric view considered the sun as the center of the universe. He learned that the sun was many time farther than the moon and that it was much larger than the earth. He also made an attempt to calculate the distance of the sun and the moon by using geometric principles. He based his calculations ...